// Copyright (c) 1998-2002, Distributed Real-time Computing Lab (DRCL) 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice,
//    this list of conditions and the following disclaimer. 
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution. 
// 3. Neither the name of "DRCL" nor the names of its contributors may be used
//    to endorse or promote products derived from this software without specific
//    prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 

package drcl.inet.mac;

import java.math.*;
import drcl.inet.*;
import drcl.net.*;
import drcl.comp.*;

/** 
 * TSFTimer to simulate clock difference 
 * @see Mac_802_11
 *
 * @author Rong Zheng
 */
public class TSFTimer extends Module{
    long last_;
    long offset_;
    Mac_802_11  host_;

	/** Create an instance of TSFTimer. Set offset_ to 0 to simulate synchronized network from the very beginning */
    public TSFTimer(Mac_802_11 h, int index) {
		host_ = h;
		//offset_ = (long)(Math.random()*(1<<32) + Math.random()*(1<<16));
        offset_ = 0;
	}

    public long getTSF() {
		return offset_ + (long)(host_.getTime() * 1e6);
	}

    public void setTSF(long tsf) {
		offset_ = tsf - (long)(host_.getTime() * 1e6); 
	}
 
};
